[XGen]

The reaction 2HCl  H2 + Cl2 has K = 3.2 x 10^-34 at 298K. The initial partial pressures are: H2, 1.0 bar; HCl, 2.0 bar; and Cl2, 3.0 bar. At equilibrium there is 1.0 mol H2. What is the volume of the container?

I set up a normal expression, (1 - x)(2 - x)/(3 + 2x) = 3.2 x 10^-34. However, it's very hard to approximate an answer. The answer key says 9.7 x 10³³ L, which comes out to about 3.9 x 10^-34 bar for H2; however, I don't know any reasonable method to get to an answer like this. Can anyone help me out?

[Borek]

Instead of using x that is amount of hydrogen that reacted, use x that is amount of hydrogen that is left. Then remember that 1-something very small is well approximated by 1.

Not that I checked it yields the correct answer.